Copying system for cutting out articles of complex shape by the electroerosion method

ABSTRACT

A copying system for cutting out articles of complex shape by the electroerosion method, which for the purpose of using enlarged drawings as master-forms has a traverse that swings about an axis passing through one end thereof, and carries an electrode-tool, its other end carrying a pickup, the traverse being swung by one of the drives of the tracing system. The copying system also has a supplementary carriage moved by the second drive of the tracing system, and connected to the board of the master-form by means of a flexible tie, while its connection with the carriage whereon secured is the working table, is realized through a sine converter disposed on said supplementary carriage and capable of regulating its angle of inclination.

United States Patent Veroman et al.

[ 1 June 27,1972

[54] COPYING SYSTEM FOR CUTTING OUT ARTICLES OF COMPLEX SHAPE BY THEELECTROEROSION METHOD Primary Examiner-R. F. Staubly Attorney-Waters,Roditi, Schwartz & Nissen [72] Inventors: Vlktor Jurlevieh Veroman,ulitsa Soldata [57] ABSTRACT korzuna, 3, kv. I59; Vladimir AlexeevichTikhoretsy Prospekt, 9, 'p A copying system for cutting out articles ofcomplex shape by Mikhlil Yikovlevich the electroerosion method, whichfor the purpose of using en- Rabinovreh, uhtsa Rustavell, l8, kv- 40, alarged drawings as master-forms has a traverse that swings of Leningrad,about an axis passing through one end thereof, and carries an [22]Filed: June 7 1971 electrode-tool, its other end carrying a pickup, thetraverse being swung by one of the drives of the tracing system. The[21] Appl. No.: 150,397 copying system also has a supplementary carriagemoved by the second drive of the tracing system, and connected to the[52] U 8 CL 219/69 v board of the master-form by means of a flexibletie, while its [51] In. .Cl 23p 1/12 connection with the carriage whensecured is the working [58] Field G 69v table, is realized through asine converter disposed on said supplementary carriage and capable ofregulating its angle of [56] References Cited 'nclmamn- UNITED STATESPATENTS 1 Chin. 1 n i Figure 3,614,372 lO/l97l Dulebon et aL; ..2l9/69 Ez i j' 5 9 5; 3 2 E Y 2 D k ii I L'- 7 [Z ir j 5 i l5 ,4 23 l9 l3 l7 122 COMPLEX SHAPE BY THE ELECTROEROSION METHOD The invention relates toequipment for electroerosion working, and more specifically to copyingsystems for cutting out articles of complex shape by the electroerosionmethod.

The invention can be used to produce articles with a cylindr-icalgenerauix and having any shape, however complex, from ordinary metals,i.e. brass, copper, aluminum, steel, etc., as 'well as from hard-to-workmetals and alloys, chilled and alloy steels, hard alloys, tungsten,molybdenum, titanium, etc.

A copying system for electroerosion cutting of articles of complexconfiguration permits manufacturing templets and patterns for checkingturbine blades and pressing dies, male and female blanking dies,profiled tools, cutters, and other components whose production by theordinary methods is either difficult, or impossible. The copying systemfor cutting out intricate articles by the electroerosion method isemployed in the tool shops of almost every industry, as well as ininstrument making, radio engineering, jewelry, and other industries.

The basic principle of operation of a copying system to cut out articlesof complex shape by the electroerosion method consists in cutting out acomponent from a solid blank using a thin wire electrode-tool, themovement of the latter being determined either by a present program, orby a given masterform. Known in the art are. machines with aprogram-controlled following of the contour being cut, wherein theprogram of movement is set in the form of punched tapes or cards.

Also known are copying cutting machines, wherein movement along thespecified contour is realized manually by the operator, orautomatically, following a metal or photosensitive master-forms made toa scale of 1:1 with respect to the job.

In the copying systems for electroerosion cutting of articles of complexshape in copying cutting machines, the electric signal from the pickupthat traces the contour of the masterform arrives at a tracing systemwith two drives, which move in a mutual proportion a board with themaster-form and a carriage with the working table secured thereon.

The main disadvantage of the program-controlled machines consists in thesignificant labor consumption required to design the programs, whichcalls for skilled engineering and technical personnel of designers.Exploitation of programcontrolled machines is quite expensive, and canrepay itself only in large-scale production. Their cost is very high.

The main disadvantage of the copying cutting machines is the large laborconsumption to make the metal or photosensitive master-forms. To producethe master-forms, specialists of precision pattem-making work must beemployed, and special technology, as well as precision machines andspecial equipment, used. When the article has a very complexconfiguration it turns out altogether impossible making a master-formthat equals the article in size.

An object of the invention is to provide a copying system forelectroerosion cutting of articles of intricate shape, that would enableusing master-forms made to an enlarged scale.

Another object of the invention is to devise a copying system, thatwould be simple in its servicing and its production.

The idea of the invention consists in that a copying system for cuttingout articles of complex shape by the electroerosion method, wherein theelectric signal from the pickup tracing the contour of the master-formarrives at a tracing system with twodrives which move in a mutualproportion a board with connection to the carriage whereon secured isthe working table, is realized through a sine converter disposed on saidsupplementary carriage and capable of regulating its angle ofinclination, whereas servingas the master-form is an enlarged drawing.

Such a design of the copying system permits using drawn master-forms,and producing components of complex configuration that would beotherwise impossible tomake. Besides, the accuracy of cutting work israised, since the requirements for the accuracy of the enlarged drawnmaster-form are reduced as many' times, as the drawn master-form isenlarged. This is why drawn master-forms can be made by low-skillworkers.

Since the copying system for electroerosion cutting of articles ofcomplex shape moves along the drawn master-form automatically, withouthuman participation, this permits employing therewith low-skilloperators.

The invention is further explicated by the description of anillustrative embodiment thereof, and by the appended drawing which showsthe copying system according to the invention.

The copying system for electroerosion cutting of articles of complexshape is employed in electroerosion machines, and realizes the cuttingprocess by the method of using a wire electrode-tool that copies theoutlines of a drawing made to an enlarged scale. Used in this system ismovement in a mixed polar-linear frame of axes, wherein continuousfollowing of the outlines of a drawing of any degree of complexity canbe achieved.

According to the invention, the copying system has a traverse l swingingabout a pivot 2, and constituting a lever of the second kind.

Secured at the end of the traverse is a pickup 3 of a tracing system 4.A wire electrode-tool 5 together with a winding system 6 are fixed on acarriage 7 which is capable of moving along traverse l by means of ascrew 8 and a handle 9. The angular movement of traverse l is done by adrive consisting of a feeding electric motor 10 which is actuated by thetracing system 4. Current pulses are supplied to the electrode-tool 5from a pulse generator 11.

Thus, the scale of the radius value in the polar-linear system ofcoordinates is determined by the position of the axis of theelectrode-tool 5 (i.e. of carriage 7) with respect to the rotation axis2 of traverse l, and is checked by measuring scaled means (not shown inthe drawing).

In this case the scale factor will be M, U],

where M, is scale factor of the angle coordinate;

L is the distance between the rotation axis 2 of traverse l and the axisof pickup 3;

[is the distance between the rotation axis 2 of traverse l and the axisof the electrode-tool 5;

Linear displacement in scale, of a board 12 with the drawing 13, and ofthe working carriage l4 whereon fixed is the blank 15, is realized bymeans of a supplementary carriage 16 located on which is a sineconverter in the form of a sine bar 17. The supplementary carriage 16 isconnected to board 12 by a flexible tie in the form a rope 18 through apulley system 19 and 20.

The supplementary carriage 16 is driven by an electric motor 21 which isalso actuated by the tracing system 4, this carriage moving in adirection perpendicular to the direction the master-form and a carriagewith a working table secured thereon, according to the invention, has atraverse that swings about an axis passing through one end thereof, andcarries an electrode-tool, its other end carrying said pickup, and thetraverse being swung by one of the drives of the tracing system, andalso has a supplementary carriage moved by the second drive of thetracing system, and connected to the board of the master-form by meansof a flexible tie, while its of movement of board 12 and the workingcarriage l4.

The supplementary carriage l6'is connected with the working carriage 14through a roller 22 secured on carriage l4 and leaning against theworking surface of bar 17 to which it is pressed by means of a weight23,. Tension of rope 18 and closure of plays in the system are achievedby means of a weight 24.

The scale of linear displacement of the working carriage 14 relative toboard 12 with drawing 13 is determined by the angle of inclination a ofbar 17 with respect to the line of movement of the supplementarycarriage 16. For the case of the arrangement of rope 18 as shown in thediagram, the scale factor of the longitudinal coordinate M will be M N2tg a, where 2 is the reduction ratio of the system of pulleys 19 and 20.

Automatic movement along the line of drawing 13 is accomplished by meansof a conventional tracing system 4 which controls the feed motors l and21 so, that the line of drawing 13 continuously passes under theobjective of pickup 3. The combined effect of the swinging of traverse land the linear displacement of board 12 provides for accordingly (i.e. Mand M, times) reduced swinging of the axis of the electrode-tool andlinear displacement of the working carriage 14 with blank 15, as aresult of which cut out from blank 15 by the electroerosion method isthe required figure reduced M and M times as compared to the drawnmaster-form 13. To maintain similarity of drawing 13 with the articlebeing cut out, the following condition should be observed:

The copying system functions as follows.

The geometrical position of the line of drawing 13 is by means of theelectronic-optical pickup converter 3 converted into an electric signalwith phase modulation. This signal arrives at the electronic tracingsystem 4 wherefrom, after a series of transfonnations and amplification,it is sent to the feed motors and 21 which swing traverse l with thewire electrode-tool 5 about pivot 2, and move the supplementary carriage16. Bar 17 disposed on carriage 16 at an angle to its direction ofmovement presses against the driving roller 22, thus bringing intomovement the working carriage 14 with blank 15 fixed thereon. At thesame time the supplementary carriage 16 through pulleys l9 and and rope18 transmits motion to board 12 with drawing 13.

Since the one-stage pulley tackle 19-20 has a transmission ratioequaling 2, the displacement of board 12 is twice longer than that ofthe supplementary carriage 16.

The displacement value of the working carriage l4 depends on the angle aofbar 17.

Thus, the displacement of board 12 will be multiplied relative to thedisplacement of the working carriage 14 with blank 15, and the scale ofmultiplication will depend only on angle a of bar 17.

The scale of multiplication of the angular movement of pickup 3 relativeto that of the electrode-tool 5 is determined by the simple ratio of thearms of tool 5 and pickup 3 with respect to the rotation axis 2.

Thus, the combined displacement in both coordinates, i.e. displacementsof traverse 1 with pickup 3 and the electrodetool 5, of board 12 withdrawing !3, and of the working carriage 14 with blank 15, results inthat each point of the line of drawing 13 continuously passes under theaxis of pickup 3.

At the same time the wire electrode-tool 5 cuts out by electric erosiona reduced copy of the drawn master-form 13 from the blank.

What we claim is:

1. A copying system for electroerosion cutting of articles of complexshape in electroerosion machines by the method of using a wireelectrode-tool that copies the lines of an enlarged drawing, comprising:a board to fix said drawing; a first carriage to fix said board; asecond carriage to mount the working table of the machine with the job;a pickup to trace the lines of the drawing, which is disposed over saidboard; a tracing system electrically connected with said pickup andhaving two drives, one of which moves in a mutual proportion said firstand second carriages; a traverse at one end of which said pickup ismounted, and connected to which is said electrodetool of the machine; apivot of said traverse passing through its other end, and about whichsaid traverse swings while the article is being cut out, said traversebeing driven by said second drive of the tracing system; a thirdcarriage moved by said first drive of the tracing system; a flexible tieby which said third carriage is connected to said first carriage, totransmit motion to the latter; a sine converter located on said thirdcarriage and capable of regulating its angle of inclination, whichinteracts with said second carriage.

1. A copying system for electroerosion cutting of articles of complexshape in electroerosion machines by the method of using a wireelectrode-tool that copies the lines of an enlarged drawing, comprising:a board to fix said drawing; a first carriage to fix said board; asecond carriage to mount the working table of the machine with the job;a pickup to trace the lines of the drawing, which is disposed over saidboard; a tracing system electrically connected with said pickup andhaving two drives, one of which moves in a mutual proportion said firstand second carriages; a traverse at one end of which said pickup ismounted, and connected to which is said electrode-tool of the machine; apivot of said traverse passing through its other end, and about whichsaid traverse swings while the article is being cut out, said traversebeing driven by said second drive of the tracing system; a thirdcarriage moved by said first drive of the tracing system; a flexible tieby which said third carriage is connected to said first carriage, totransmit motion to the latter; a sine converter located on said thirdcarriage and capable of regulating its angle of inclination, whichinteracts with said second carriage.